Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16H—GEARING
  • F16H9/00—Gearings for conveying rotary motion with variable gear ratio, or for reversing rotary motion, by endless flexible members
  • F16H9/02—Gearings for conveying rotary motion with variable gear ratio, or for reversing rotary motion, by endless flexible members without members having orbital motion
  • F16H9/04—Gearings for conveying rotary motion with variable gear ratio, or for reversing rotary motion, by endless flexible members without members having orbital motion using belts, V-belts, or ropes
  • F16H9/10—Gearings for conveying rotary motion with variable gear ratio, or for reversing rotary motion, by endless flexible members without members having orbital motion using belts, V-belts, or ropes engaging a pulley provided with radially-actuatable elements carrying the belt
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16H—GEARING
  • F16H55/00—Elements with teeth or friction surfaces for conveying motion; Worms, pulleys or sheaves for gearing mechanisms
  • F16H55/32—Friction members
  • F16H55/52—Pulleys or friction discs of adjustable construction
  • F16H55/54—Pulleys or friction discs of adjustable construction of which the bearing parts are radially adjustable

Definitions

• This invention relates to improvements in the operating system, method and apparatus for flat belt continuously variable transmission systems utilizing variable ratio pulleys.
• Such pulleys are of the nature disclosed in U.S. Patents Nos. 4,295,836, October 20, 1981 and 4,591,351, May 27, 1986, Emerson L. Kum , and it is an object of the invention to provide an improved system method and apparatus of the nature indicated.
• the disclosures of these two patents are incorporated by reference into this specification.
• Systems of the nature disclosed in the two patents referred to utilize two variable ratio pulleys connected by a flat belt.
• variable ratio is achieved by making each pulley of two pairs of pulley disks, one pair of which is inside of the other pair such that the space between the inner pulley disks defines a space within which the flat belt runs.
• the inner pulley disks of each pulley are connected rigidly together so as to run as a unit and each pulley disk has logarithmic spiral guideways in it.
• the two outer pulley disks are also connected together as a unit and each of them includes logarithmic spiral guideways therein.
• the spiral guideways of the inner set of pulley disks are directed in one sense, clockwise or counterclockwise proceeding to larger radii, and the logarithmic spiral guideways in the outer set of pulley disks are directed in the opposite sense.
• a belt drive system comprising a 4 driving pulley and a driven pulley, a belt extending 5 around the pulleys, each of the driving and the driven Q pulleys including a first pair of inner pulley disks 7 having logarithmic spiral guideways of one sense formed 8 therein and mounted for rotation as a unit on a shaft and , fixed to the shaft and a second pair of outer pulley 2 disks having logarithmic spiral guideways of an opposing
• Fig. 1 is a sectional view, partially broken away, of apparatus according to the invention and may be considered to have been taken along the lines 1-1 of Fig. 2;
• Fig. 2 is a partial sectional view taken substantially in the direction of arrows 2-2 of Fig. 1;
• Fig. 3 is a sectional view taken substantially in the direction of arrows 3-3 of Fig. 2;
• Fig. 4 is a fragmentary view partially diagrammatic and on a smaller scale taken substantially in the direction of the arrows 4-4 of Fig. 1;
• Fig. 5a is a view taken substantially in the direction of arrows.5-5 of Fig. 4;
• Figs. 5b and 5c are enlargements of two specific portions of Fig. 5a showing the forces involved;
• Figs. 5d and 5e are enlargements at approximately the same locations as Figs. 5b and 5c, but with the belt direction reversed;
• Fig. 6a is a view similar to Fig. 5a with the sense or direction of the spiral grooves reversed relative to those in Fig. 5a;
• Figs. 6b and 6c are enlargements of portions of Fig. 6a in approximately the same locations as those enlargements of Figs. 5b and 5c;
• Fig. 7 is a fragmentary .diagrammatic view taken at the location of any belt drive element.
• the pulleys 11 and 12 are essentially identical to each other with the exception of the sense or direction of the logarithmic spiral guideways therein as will be explained.
• the pulley 11 is mounted on a shaft 14 and the pulley 12 is mounted on a shaft 15. Inasmuch as the pulleys are essentially duplicates of each other only the driven pulley 12, its shaft and related structure will be specifically described as shown in Fig. 2.
• the shaft 15 is supported in the frame 13 by means of well-known types of ball bearings 16 and 17.
• the pulley 12 comprises a pair of inner guideway disks 18 and 19 and a pair of outer guideway disks 21 and 22.
• the inner guideway disks 18 and 19 are press fitted onto a collar 23 which surrounds the shaft 15 and is keyed thereto by keys 24 disposed in keyways on the shaft 15.
• the inner guideway disks 18 and 19 accordingly form a rigid unitary structure which rotates as a unit with the shaft 15.
• the outer guideway disks 21 and 22 are press fitted onto a collar 25 which also surrounds the shaft 15 and is interior of the collar 23.
• the collar 25 is rotatably moveable within prescribed limits as will be made clear.
• the outer guideway disks .11 and 12 thus also are rigidly connected to each other and operate as a unit even though rotatably mounted on the shaft 15.
• the keys 24 project through a circumferential slot 20 in the collar 25 for the keys 24 to move therein when the outer guideway disks 21, 22 and collar 25 assembly rotates relative to the inner guideway disk 18, 19 and collar 23 assembly during operation as will be explained.
• the drive pulley 11 is partially shown in Fig. 2, the inner guideway disks being 26 and 27 and the outer guideway disks being 28 and 29.
• the inner guideway disks 18 and 19 and the outer guideway disks 21 and 22 of pulley 12 are flat disks lying immediately adjacent each other as may be visualized in Fig. 2.
• the inner guideway disks 26 and 27 and the outer guideway disks 28 and 29 of pulley 11 are flat disks and lie immediately adjacent to each other essentially as shown.
• the inner guideway disks 18 and 19 have logarithmic spiral guideways 31 and 32 therein, respectively, and the outer guideway disks 21 and 22 have logarithmic spiral guideways 33 and 34 formed therein as will be more particularly described.
• the inner guideway disks 26 and 27 have logarithmic spiral guideways 35 and 36 therein and the outer guideway disks 28 _and 29 have logarithmic spiral guideways 37 and 38 therein, as will be more particularly described.
• the logarithmic spiral guideways 31 and 33 intersect with each other as do the logarithmic spiral guideways 32 and 34 of pulley 12. Extending between these intersections is a belt drive element 39. Referring to Fig. 1 it will be seen that there is a belt drive element 39 at the intersections -of the logarithmic spiral guideways in each of the inner and outer guideway disks 19 and 22 respectively. Similarly, in the case of the driving pulley 11 there is a belt drive element 41 at the intersection of each of the logarithmic spiral grooves in the inner and outer guideway disks 27 and 29 respectively.
• a particular belt drive element 41a is shown at the intersection of the logarithmic spiral guideways 36 and 38 of inner and outer guideway disks-27 and 29, respectively. It may be visualized that as the outer guideway disk 29 rotates counterclockwise relative to the inner guideway disk 27 the particular belt drive element 41a will move inwardly toward the center of the shaft. This would continue until the inner end of the logarithmic guideway 36 and the inner end of the logarithmic guideway 38 intersect and the belt drive element 41a is at its innermost position, for example, as shown for belt drive elements 39 of pulley 12 of Fig. 2.
• the logarithmic spiral guideways 36 and 38 of guideway disks 27 and 29 intersect at right angles to each other as is characteristic of the preferred logarithmic spiral thereby forming a substantially square bearing area having four sides against which the square ends of the belt drive elements may bear in being part of the driving or driven pulley.
• the belt drive elements 39 and 41 have a drive surface 42 which lies on the center line of the square ends 43 and 44 of the belt drive elements. Reduced stresses are thus achieved as is considered in the Kumm patent 4,591,351.
• the belt drive elements 39, 41 extend between the inner and outer guideway disks.
• the belt drive elements move inward radially and outward radially, respectively, as required by a belt 45 of fixed length which is wrapped around them. Additional details of the guideway disks and the belt drive elements may be found in the Kumm patents referred to.
• the outer guideway disk assembly is rotatable within a limited extent relative to the inner guideway disk assembly as has already been indicated, this being carried out by, for example, by a hydraulic mechanism now to be briefly described.
• a similar mechanism and one which may be used here is disclosed in the Kumm patent 4,295,836.
• the hydraulic mechanism is identified by the reference character 46 which comprises a closed chamber 47 having four walls, in effect, 48, 49, 51 and 52, the wall 51 being adapted to be attached to and rotating with the outer guideway disk 21 using, for example, pins 53.
• the inner and outer walls of the chamber 47 are sealed relative to the shaft 15 so that hydraulic pressure supplied to the chamber 47 through a central passageway 54 in the shaft 15 will supply pressure for causing the inner and outer guideway disk assemblies to rotate relative to each other.
• FIG. 3 there is shown a sectional view of the hydraulic mechanism wherein the outer wall 49 includes a pair of housing struts 55 and 56 and integral therewith.
• the inner wall 52 is, in effect, a collar surrounding the shaft 15 and keyed thereto by keys 57.
• the collar (wall) 52 includes a pair of shaft struts 58 and 59 integral therewith. It is evident that the spaces between the housing struts 55 and the shaft struts 58 define chambers whereby the shaft strut 58 may assume various positions depending upon the hydraulic pressure within the chamber, the hydraulic pressure being supplied through appropriate passageways in shaft 15.
• the hydraulic means described, namely the chamber 47 and operating components which rotate the outer guideway disks relative to the inner guideway disks may be termed the hydraulic rotary actuator.
• the manner of supplying hydraulic pressure to the hydraulic means 46 including the apparatus as described is not a specific part of the invention disclosed in this application.
• the hydraulic means 46 is one of a type that may be used to supply the necessary hydraulic pressure. That system disclosed in the Kumm patent 4,295,836 also is one which will serve that same purpose. Others, of course, may be devised.
• Applicant has discovered that there is a relationship between the direction or sense of the logarithmic spiral guideways as between the driving and the driven pulley and with respect to the direction of belt rotation. This is the substance of the subject invention. Applicant has discovered that by selecting the logarithmic spiral guideways of the driving pulley and the driven pulley to be in the opposite senses relative to each other and that the sense of the logarithmic spiral guideways in the guideway disks not connected to the hydraulic rotary actuator in the driving pulley should be opposite to that of the direction of belt movement and as to the driven pulley the direction of the logarithmic spiral guideways in the guideway discs not connected to the hydraulic rotary actuator should be the same as the direction of belt movement.
• Fig. 5a is in effect a sectional view taken in the direction of arrows 5-5 " of Fig. 4 and Fig. 6a is similar to Fig. " 5 except that the sense or direction of the logarithmic spiral guideways is reversed.
• Fig. 5a which is in effect, a figure reduced in size and similar to Fig. 1 in the showing of the logarithmic spiral guideways of the pulleys and other mechanisms.
• the logarithmic spirals 36 of inner guideway disk 27 extend in the opposite 1 direction as compared to the direction of belt movement 2 shown by the arrow A.
• Fig. 5b there is shown an enlargement of the 2 inner section between the logarithmic spiral guideway 36 3 and logarithmic spiral guideway 38 together with the 4 forces acting thereon when moved by the belt 45.
• BFF Belt Friction Force
• NRF Net radial force which is at right 8 angles to the direction of the belt frictional force
• the ratio of frictional force relative to the 3 belt direction to the belt radial force perpendicular to 4 the belt direction is the effective coefficient of 5 friction and this could be a value varying over a wide 6 range, for example, from .02 or .03 to values larger than 7 1.
• Particular belt materials, for " example, and belt 8 drive element materials are chosen to give the desired g high values for the friction coefficient.
• Q NRF being the net radial force is defined as the 1 radial force resulting from the belt tension and the 2 change in direction of belt passing over the belt drive 3 element diminished by the centrifugal force of the belt 4 drive element.
• Resolving the 9 force FR into the components F3 and F4 illustrates that 0 the component F3 is small and the component F4 is large.
• 1 F4 is the force of side 4 of the drive element end 43 2 against the logarithmic spiral guideway 36 which is part 3 of the inner guideway disk 27 and thus is supported 4 directly by the mechanical structure through to the shaft 5 15.
• F3, which is the small component is the force of 6 side 3 of the drive element end 43 against the 7 logarithmic spiral guideway 38 which is part of the outer 8 guideway disk 29 and thus is opposed or balanced by the 9 hydraulic pressure in the chamber 47, i.e., is balanced 0 by the hydraulic rotary actuator.
• the resultant force FR of the forces BFF and NRF may then be resolved into forces; Fl of side 1 of the drive element end 43 against the logarithmic spiral guideway 34, and F4 of side 4 of the drive element end 43 against the logarithmic spiral guideway 32.
• the force F4 which is the larger of the forces F4 and Fl is exerted by side 4 against lo.garithmic guideway 32 and thus is supported by the mechanical structure directly down through to the shaft 15.
• the smaller of the forces, Fl is exerted by side 1 and thus is balanced by the hydraulic pressure in the rotary actuator as previously described. It is to be noted that both in the cases of 5b and 5c the force Fl, • which is balanced by the hydraulic forces, is the smaller of the forces involved.
• Fig. 6a which is the same as Fig. 5a except that logarithmic spiral guideway 36 of Fig. 5a is shown as logarithmic spiral guideway 36a (the driving pulley) of Fig. 6a, the logarithmic spiral guideway 36a being in the opposite sense to that of logarithmic spiral 36 of Fig. 5a.
• the logarithmic spiral guideway 38 of outer guideway disk 29 is shown as logarithmic spiral guideway 38a of Fig. 6a and is in the reverse sense or direction as compared .to logarithmic spiral 38.
• the logarithmic spiral 32a is in the reverse sense to logarithmic spiral 32 of Fig.
• the forces shown in Fig. 6b correspond to those existing on the end 43 of the belt drive element 41 with the reverse sense of the logarithmic spiral groove and may be compared with the forces and the parts sustaining them as shown in Fig. 5b.
• the force F3 ' is substantially identical in magnitude to the force F3 in Fig. 5b
• the force F4 is substantially identical in magnitude to the force F4 in Fig. 5b, these forces having been arrived at by the resolution of the belt friction force BFF and the net radial force NRF in the same manner as for Fig. 5.
• the force F3, the smaller of the forces, is now exerted by the side 3 of the end 43 of belt drive element 41 against the logarithmic spiral guideway 36a.
• the force F4 by far the larger of the forces, is exerted by side 4 of the end 43 of belt drive element 41 against the side of the logarithmic spiral 38a of outside guideway disk 29 and thus is balanced by the hydraulic pressure in the rotary actuator which is connected to the guideway disk 29.
• the force F4 requiring hydraulic balancing pressure is much greater than F3 in Fig. 6b.
• F4 is the force which is supplied mechanically through the structure to the shaft 15 and illustrates that in the case of the reversed belt direction, the mechanical connection to the shaft 15 supports a much smaller force F4 than the larger force F4 of Fig. 5c.
• the force F ] _ which is that balanced by the hydraulic pressure in the rotary, actuator is much larger in the reversed belt case of Fig. 5e as compared with the regular belt direction operation Fl of Fig. 5 ⁇ .
• FIG. 7 there is shown 1 diagrammatically a belt drive element 39, 41 which has a 2 drive surface 42 depressed, or offset, to correspond with 3 the center line of the end 43 of the belt drive element. 4
• Two guideway disks, for example, 27 and 29 are shown as 5 supporting the end portion 43. It will be recalled that 6 the inner guideway disk 27 is that supported mechanically 7 in a direct fashion by the shaft of the structure and the 8 guideway disk 29 is that supported by the hydraulic 9 pressure in the rotary actuator.
• the bending moment 3 existing at the juncture J between the end portion 43 and 4 the center part or belt engaging portion 42 is much 5 reduced, as compared with the case where the guideway 6 disk 27 would be at the end of the end member 43, at the location of the outer guideway disk ' 29, which is that 8 supported by the hydraulic pressure in the rotary 9 actuator.
• the 1 bending moment existing in the belt drive element is 2 reduced by having the inner guideway disk structure 3 supported directly and mechanically on the shaft of the 4 device while at the same time the operating pressure in 5 the hydraulic actuator is reduced by having the 6 logarithmic spiral guideways of the driving pulley in the 7 same sense as the belt movement and in the reverse sense 8 in the driven pulley.
• springs could also be used in the

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• 1986
  • 1986-06-06 US US06/871,254 patent/US4714452A/en not_active Expired - Fee Related
• 1987
  • 1987-06-04 NL NL8720274A patent/NL8720274A/nl unknown
  • 1987-06-04 WO PCT/US1987/001324 patent/WO1987007693A1/fr not_active Application Discontinuation
  • 1987-06-04 EP EP19870903979 patent/EP0273930A4/fr not_active Withdrawn
  • 1987-06-04 GB GB08730353A patent/GB2199096A/en not_active Withdrawn
  • 1987-06-04 BR BR8707339A patent/BR8707339A/pt unknown
  • 1987-06-04 JP JP62503611A patent/JPH01500608A/ja active Pending
  • 1987-06-04 KR KR1019880700140A patent/KR880701340A/ko not_active Application Discontinuation
  • 1987-06-04 AU AU75405/87A patent/AU7540587A/en not_active Abandoned
  • 1987-06-04 DE DE19873790302 patent/DE3790302T1/de not_active Withdrawn
  • 1987-06-05 ES ES8701662A patent/ES2006160A6/es not_active Expired
  • 1987-06-06 CN CN198787104105A patent/CN87104105A/zh active Pending
• 1988
  • 1988-02-02 SE SE8800326A patent/SE8800326L/xx not_active Application Discontinuation

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